Tobacco smoke filter

ABSTRACT

A tobacco smoke filtering means having passageways through which the smoke passes, the passageways being defined by substantially spherical dielectric particles each of which is electrostatically charged so as to manifest a positive charge on one side and a negative charge on its opposite side.

United States Patent [72] inventors JohnH.Troll 2305 Andrews Ave., Bronx; Alan N. Aldern, 88 Remsen St., Breaklyn, N.Y. l 1212 [21 Appl. No. 739,965

[22] Filed May 21, 1968 Division ofSer. N0. 634,196, Apr. 27, 1967, Pat. 3,463,168

1451 Patented Air. 20, 1971 [54] TOBACCO SMOKE FILTER 3,087,500 4/1963 Jacobson 131/107 3,354,373 11/1967 Fatovic ....(131/262BUX) 2,815,760 12/1957 Schrens et a1 (131/262UX) 2,839,065 6/1958 Milton 131/261X 2,916,038 12/1959 Wade (131/262UX) 3,030,964 4/1962 Whitmore l3 l/262X FORElGN PATENTS 292,479 6/1929 Great Britain 131/2628 518,087 2/1931 Germany 131/262 OTHER REFERENCES Mechanix Illustrated March 1968 p. 10

Primary Examiner-Melvin D. Rein Att0rneyDavis, Hoxie, Faithfull & Hapgood ABSTRACT: A tobacco smoke filtering means having passageways through which the smoke passes, the passageways being defined by substantially spherical dielectric particles each of which is electrostatically charged so as to manifest a positive charge on one side and a negative charge on its opposite side.

PATENTE0APR20|91| /n venfors John H. 7/0// A lah A/pem Attorneys TOBACCO SMOllflE FILTER This is a division of copending application Ser. No. 634,196 filed Apr. 27, 1967 entitled Tobacco Smoke Filter," now US. Pat. No. 3,463,168.

This invention relates to a product for the removal of harmful portions of tobacco smoke. More particularly, it relates to a filter for removing from tobacco smoke positively charged particles, negatively charged particles and electrostatically neutral particles by electrostatic attraction onto the surface of a polarized dielectric material.

Recent scientific evidence has established the presence of electrostatically charged and uncharged particles and radioactive elements, in particular Polonium 210, in cigarette smoke which enter the smokers bronchial airways and produce various harmful effects amongst which are carcinogenic effects and a causal relationship or, at least, an association with bronchitis, emphysema, cardiovascular and other diseases. One of the principal factors involved which can be considered a cause of these detrimental effects is the inhibition of the cilial activity through which particles are removed from the bronchial airwaves. Such inhibition apparently enables environmental carcinogens to reach the epithelial cells. It has been shown that positive ions are a cilial depressant and such ions are derived from alpha particle reduction of Polonium 210. Furthermore, radioactive Polonium 210 is negatively charged, thus explaining the presence of at least one type of harmful electrostatically negative particle. The radiation dose absorbed by smokers is substantial and, furthermore, the synergistic action of ionizing radiation with the other chemical agents present in tobacco smoke may have a significantly detrimental effect. In addition to these electrostatically charged particles, there also are present in tobacco smoke a large number of neutral colloidal particles whose physical presence in the bronchial airways may be harmful. Some arise for instance, from negatively charged Polonium 2l0 combined with positively charged ions. The Polonium particles continue as radioactive colloidal particles which should be filtered out of the smoke.

BACKGROUND Previous filters relied upon mechanical traps which, no matter how efficient, do not remove the harmful ingredients of the gaseous phase of the smoke. Electrostatic filters have been developed for removing particles of a single electrostatic charge only. Many of these filters require an external electric power source. This invention provides a filter that specifically removes particles which are positively charged, negatively charged and neutral from the mainstream of the smoke before they make contact with any portion of the smokers anatomy without requiring any external source of electric power and without altering materially the physical shape of, or established manufacturing procedures for, tobacco or tobacco articles such as cigarettes. The removal is performed by causing the tobacco smoke to flow adjacent to filter elements which have dual electrostatic charges; i.e. positive and negative, in series alignment with the smoke flow path.

Accordingly, it is one object of this invention to provide an improved tobacco smoke filter and method for removing positively charged, negatively charged and neutral particles from tobacco smoke.

It is another object of this invention to provide such a filter which is exceptionally efficient, inexpensive to produce and utilize, and which can be readily adapted for use with any type of smoking article.

BRIEF DESCRIPTION Certain materials are particularly suitable for use as a tobacco smoke filter since they are capable of being electrostatically charged and holding their charge for long periods of time, for example two years and more. Such materials, which are considered to be "permanently" charged, are dielectrics and are referred to herein as electret material" and the material when charged is called an electret." Electrets may be introduced directly into the tobacco of the smoking article or may be incorporated into a separate unit through which the tobacco smoke flows prior to entry into the smokers bronchial airways. It is important that such filters include electrets having both positive and negative charges and that the electrets be arranged such that the tobacco smoke, in passing through the smoking article, contacts electrets of both polarities. The positively charged electrets attract the negatively charged particles, the negatively charged electrets attract the positively charged particles and the neutral particles, upon being exposed to electrets of one polarity, will become charged with that polarity and be attracted to the subsequently encountered electrets of the opposite polarity.

DRAWING These and other forms embodying this invention are illustrated in the following drawing in which:

FIG. l is a sectional view of a filter formed in accordance with an embodiment of this invention.

FIG. 2 is a magnified view of a portion of the filter of FIG. 1.

FIG. 3 is a schematic illustration of a method of forming spherical electrets employed in the filter of FIG. 1.

FIG. 41 is a partially cut away view of a cigarette formed in accordance with another embodiment of this invention.

A first embodiment of this invention, illustrated in FIG. 1, comprises a filter 60 adapted to be attached to the mouth end of the cigarette (not shown). The filter is formed of a mass of spherical electrets 62 packed under force into a cylindrical container 64 formed of plastic or stiffened paper. The spherical electrets 62, which preferably are of glass or a polyester resin, are formed as illustrated in FIG. 3. Electret material 66 in a molten state is contained under pressure within a hopper 63 and spherical droplets 70 of the molten electret material are ejected from the exit nozzle 72. The droplets pass between electrically charged plates 74, 76 having opposite polarities with sufiicient velocity so that the moment inertia of the droplets is larger than the electrostatic moments impressed upon the solidifying droplets. The resultant electrets 62 of spherical shape are hemispherically charged or, in other words, the hemisphere adjacent to the positive plate 74 will be charged positively while the hemisphere adjacent to the negatively charged plate 76 will be charged negatively. FIG. 2 illustrates a magnified portion of FIG. l to illustrate the hemispherical charges and a probable electret alignment.

Spherical shapes are preferred over other rounded forms in order to assure minimal contact between the adjacent electrets resulting in multiple heavily charged passageways 78 of sufficient cross-sectional area to permit a proper tobacco smoke flow stream. Furthermore, reduction of the contact area between adjacent electrets assures maintenance of the charges on the electrets for a sufficiently long period, considering their intended use. It will be observed that the hemispherical charges on the electrets assures that the tobacco smoke will be in contact with or immediately adjacent to surfaces of both positive and negative charges during its passage through the filter.

A second embodiment of this invention, illustrated in FIG. 4, comprises the use of electrets 80 having a particle size smaller than the width of tobacco shreds employed in the finished tobacco product, such as a cigarette 82. In order to prevent the electrets 80 from being inhaled in the event that no other filtering medium is employed, the electret particle size is substantially larger than the average diameter of the smoke passageways between tobacco shreds or between tobacco and paper wrapper. It has been found that the electrets should be larger than about 0.005 inch. If a mechanical filter tip of the conventional type is employed, the electrets may be smaller since they will be prevented from entering the smoker's bronchial airways by the mechanical filter.

The electrets, preferably of glass or other electret material having a melting point above the temperature to which it will be exposed, are activated by allowing them to pass from a molten to a solid state in the presence of a strong DC electric field as described above. The proper size may be obtained by dividing the electrets into particles of the desired size by any conventional means such as ejecting the molten material through fine spray nozzles, screens, or by subjecting the solidified electrets to any conventional comminuting means. The electrets are then sprayed upon or mixed with the tobacco leaves or shreds, adhering to them by electrostatic attraction. Alternatively, they may be mixed and dispersed in an electrostatically neutral, nonconductive, nontoxic and nonvolatile adhesive and sprayed on the tobacco leaves or shreds. During smoking, the permanently charged electrets 80 attract the positively charged portions of the tobacco smoke to their negatively charged portion of the surface and the negatively charged portions of the tobacco smoke to their positively charged portions of their surface thus effectively filtering the tobacco smoke.

HO. 4 illustrates that random dispersement of the electrets throughout the length of the cigarette assures that the tobacco smoke will flow adjacent to both positively charged and negatively charged surfaces throughout its flow stream.

While the above description has been directed primarily to cigarette filters, it is clear that the principles of this invention are equally applicable to filters for other smoking articles, such as cigars and pipes. Furthermore, when used they can be filters permanently mounted on cigarettes or cigars or as disposable inserts for reusable, separate filters which are adapted to receive the smoking article.

As will be apparent to those skilled in the art, various other modifications can be carried out from the above disclosure without departing from the spirit and scope of the invention embodied within the claims.

We claim:

1. A tobacco smoke filter comprising a plurality of relatively small substantially spherical electrets of glass or polyester resin, each of said electrets having on one side thereof an imposed positive charge and on its opposite side, an imposed negative charge, the electrets being confined within a housing so that smoke is forced to pass through passageways defined by the surfaces of the electrets, the electret mass being effective to remove charged particles from the smoke. 

